Caltrans D6 Active Traffic Management - Roadway Functionality
Subsystem Description
The Roadway Subsystem (RS) includes the equipment distributed on and along the roadway that monitors and controls traffic and monitors and manages the roadway itself. Equipment includes traffic detectors, environmental sensors, traffic signals, highway advisory radios, dynamic message signs, CCTV cameras and video image processing systems, grade crossing warning systems, and freeway ramp metering systems. HOV lane management, reversible lane management functions, and barrier systems that control access to transportation infrastructure such as roadways, bridges and tunnels are also supported. This subsystem also provides the capability for environmental monitoring including sensors that measure road conditions, surface weather, and vehicle emissions. In adverse conditions, automated systems can be used to apply anti-icing materials, disperse fog, etc. Work zone systems including work zone surveillance, traffic control, driver warning, and work crew safety systems are also included. To enhance security, safeguard systems such as blast shields, exhaust systems and other automated and remotely controlled systems to protect transportation infrastructure is also provided. In advanced implementations, this subsystem supports automated vehicle safety systems by safely controlling access to and egress from an Automated Highway System through monitoring of, and communications with, AHS vehicles. Intersection collision avoidance functions are provided by determining the probability of a collision in the intersection and sending appropriate warnings and/or control actions to the approaching vehicles.
Functional Area: Roadway Basic Surveillance
Field elements that monitor traffic conditions using loop detectors and CCTV cameras.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall collect, process, digitize, and send traffic sensor data (speed, volume, and occupancy) to the center for further analysis and storage, under center control. | Planned |
| 3 | The field element shall collect, digitize, and send multimodal crossing and high occupancy vehicle (HOV) lane sensor data to the center for further analysis and storage. | Planned |
Functional Area: Roadway Dynamic Lane Management and Shoulder Use
Field elements including physical overhead lane signs and associated control electronics that are used to manage and control specific lanes, including temporary use of shoulders as travel lanes.
| ID | Requirement | Status |
|---|---|---|
| 1 | The field element shall measure traffic conditions per lane, under center control. | Planned |
| 2 | The field element shall determine how to change the lane controls to respond to current traffic and road conditions. | Planned |
| 3 | The field element shall receive lane management control information from the controlling center. | Planned |
| 4 | The field element shall provide guidance and information to drivers regarding current lane configuration and status. | Planned |
| 7 | The field element shall monitor current lane usage to determine if vehicles are complying with current lane use restrictions. | Planned |
| 9 | The field element shall monitor operational status of the dynamic lane control equipment and report operational status to the controlling center. | Planned |
Functional Area: Roadway Equipment Coordination
Field elements that control and send data to other field elements (such as environmental sensors that send data to a DMS or coordination between traffic controllers on adjacent intersections), without center control.
| ID | Requirement | Status |
|---|---|---|
| 3 | The field element shall include devices that provide data and status information to other field element devices without center control. | Planned |
| 4 | The field element shall include devices that receive configuration data from other field element devices, without center control. | Planned |